Haloperidol and Phentermine and topiramate interaction
Haloperidol and Phentermine and topiramate: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Haloperidol (Haldol Decanoate) label · effective 2025-11-11
Seizures: HALDOL DECANOATE is generally not recommended in patients receiving antiseizure drugs or who have a history of seizures or EEG abnormalities.
HALDOL DECANOATE is generally not recommended in patients receiving antiseizure drugs or have a history of seizures or EEG abnormalities.
CYP3A4 Inducers Clinical Impact CYP3A4 inducers decrease haloperidol exposure (haloperidol is a CYP3A4 substrate) [see Clinical Pharmacology (12.3) ].
Concomitant use of HALDOL DECANOATE with CYP3A4 inducers may reduce the effectiveness of HALDOL DECANOATE.
Table 3: Other Clinically Significant Drugs Interactions See www.fda.gov/CYPandTransporterInteractingDrugs for examples of CYP3A4 and/or CYP2D6 inhibitors, CYP3A4 inducers, and CYP2D6 substrates.
From the Phentermine and topiramate label · effective 2026-05-18
The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence.
CNS Depressants Including Alcohol Clinical Impact The concomitant use of alcohol or CNS depressant drugs (e.g., barbiturates, benzodiazepines, and sleep medications) with phentermine or topiramate may potentiate CNS depression such as dizziness or cognitive adverse reactions, or other centrally mediated effects of these agents.
CNS Depressants Including Alcohol : May potentiate CNS depressant effects.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.